1. Field of the Invention
The present invention relates to an adjustable support for use in elevating a bed or other furniture item above a floor surface or similar substrate, by placing the support underneath the leg(s) of the bed or other furniture item. More particularly, the invention relates to such a support having a simplified, low-cost structure which can easily be adjusted between multiple stepped positions, and which is capable of securely supporting a furniture item at a desired level during use.
2. Description of the Background Art
There are many known devices for raising the height level of a furniture item by positioning the devices such that the legs of the furniture item are supported above a floor surface by the devices. Many different designs of risers and furniture-elevating apparatus may be found in class 248, subclasses 188 et seq., and the known devices use various  mechanisms for raising the height level of furniture above the floor.
Examples of some of the issued patents disclosing systems/device for raising the height level of furniture include U.S. Pat. Nos. 6,012,185, 5,899,422, 5,615,429, 5,345,631, 5,107,775, 4,312,088, 3,795,925, 2,072,791, and U.S. Pat. No. 1,670,601, some of which are discussed further below.
Eke, U.S. Pat. No. 5,899,422, issued May 4, 1999 and entitled “Adjustable Furniture Leg Extension”, discloses a system in which a rotatable support member is received within a central opening of a base, via a screw thread connection, such that the height of the rotatable member relative to the base can be adjusted by rotating the support member. A locking mechanism, such as a thumbscrew, engages the support member to temporarily lock it in a desired position. The bottom surface of the base rests on the floor, while an elongated stabilizing member extends from the base to prevent the device from easily tipping during normal use.
Woods et al., U.S. Pat. No. 6,012,185, issued Jan. 11, 2000 and entitled “Blocks For Elevating Bed Legs”, discloses a system in which a pair of stackable, nestable blocks are provide for elevating the legs of a bed. Each of the two blocks may be of a different height, so that each combination of one or both of the blocks produces a different elevation to which the bed may be lifted. Also, each of the blocks may have recesses in one or both ends of the block to receive and support the foot of the bed leg, and preferably, the depth of recesses in opposite ends of a block will be different, so that a given block may be used with either end facing upwards to achieve two different support orientations. One of the blocks is larger in size than the other such that the smaller block may be stacked/nested on top of the larger block. The  disclosed configuration gives a total of five different elevations to which the bed may be raised.
Williams, U.S. Pat. No. 5,615,429, issued Apr. 1, 1997 and entitled “Bed Elevating Blocks”, discloses a system for supporting the legs of a bed for the purpose of adjustably raising one end of the bed, including a number of stackable, molded blocks, whereby any number of the blocks may be stacked together in a nesting fashion to achieve a desired support height. A dimple is formed in the top of each block which may receive the bottom end of abed leg.
Langlais, U.S. Pat. No. 5,107,775, issued Apr. 28, 1992 and entitled “Adjustable Legs for Desk and the Like”, discloses a support apparatus including an elongate sleeve, the upper end of which fits over the lower end of a furniture leg, and a bolt which may be selectively inserted through various vertically-spaced openings defined along the sleeve and functions as a stop for the end of the furniture leg. By placing the bolt in different openings the height by which the sleeve raises the furniture leg is varied.
Webb, U.S. Pat. No. 4,312,088, issued Jan. 26, 1982 and entitled “Portable Bed Adjusting Device For Patients And The Like”, discloses a portable device for raising one end of a bed to a selected height, including male and female parts which are adjustable relative to each other via a screw thread therebetween, allowing for the height of elevation of the bed to be adjusted to the user's preference. A cavity is defined in the top member of the configuration such that a bed leg may be held stationary inside.
Leagus, Jr., U.S. Pat. No. 3,795,925, issued Mar. 12, 1974 and entitled “Bed Frame End Adjustable Height Stand”, disclosed a bed elevating system which uses a self standing base having two axial uprights disposed vertically within the base. The upper terminal  of the uprights has a notch, capable of supporting and seating a bed frame formed of angle iron or the like. An extension may be added to the upright which also has a notch in the upper terminal for supporting a bed frame. This extension allows the height of elevation of the bed to be anywhere from approximately 3 to 12 inches.
Baer, U.S. Pat. No. 2,072,791, issued Mar. 2, 1937 and entitled “Adjustable Combined Elevating and Supporting Device”, discloses a support apparatus including a support base having an elongate tubular section and a support member also having an elongate tubular section which slidably and rotatably fits within the base tubular section and has a receiving cup that receives the bottom of a bed leg or the like. The base includes multiple engagement notches/openings defined along one portion thereof, while the support member has multiple projections extending from a portion thereof and which may be selectively engages in the notches/openings for establishing different heights of the support member above a floor surface.
As will be appreciated, each of such the known devices discussed above includes structure for adjusting its relative height/length, and hence the height to which the furniture is raised above a floor surface. Although the devices function appropriately for their intended uses, there are some drawbacks and disadvantages associated with the known devices. For example, several of the known devices are limited in their range of adjustability, being adjustable only between a small number of positions. Some of the previously known devices may become unstable during use, especially when set to a high level. Some of the known devices have a tendency not to stay in a desired position unless an additional locking mechanism is provided for such purpose. Some include a relatively large number of parts that must be connected together,  especially at higher elevating positions. Some are relatively complicated and/or expensive to manufacture, some are relatively bulky, even when stored or shipped, etc.
Thus, a need still exists in the art for an improved adjustable support apparatus for raising the height of furniture above a floor surface, a device having a simple and economic construction, which is highly durable and stable during use, and permits a simple adjustment between several different positions.